$ { {4} \times \left[\begin{array}{rr}{0} & {2} \\ {0} & {-2} \\ {1} & {0}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{4}\times{0} & {4}\times{2} \\ {4}\times{0} & {4}\times{-2} \\ {4}\times{1} & {4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {8} \\ {0} & {-8} \\ {4} & {0}\end{array}\right]}$